#include <stdio.h>
#include <time.h>
long fn();
int main(void){
    time_t startTime,endTime;
    time(&startTime);
    fn();
    time(&endTime);
    double res = difftime(endTime,startTime);
    printf("执行时间：%lf\n",res);
    return 0;
}
 
long fn(){
    long sum=0;
    for(long i=0;i<10000000;i++){
        for(long j=0;j<100;j++){
            sum+=j;
        }
    }
    return sum;
}